JP5375584B2 - Electronics - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electronic equipment for appropriately using the extended information of a GPS system. <P>SOLUTION: The electronic equipment 1 includes: a positioning means 20 for using first information from satellites 201, 202 or second information replaced with the first information to obtain position information; a power source supply means 17 for supplying a power source to the positioning means 20 so that a power source switch 18 obtains the position information at a prescribed interval during an off-state; a first storing means 14 for storing extended information necessary for the calculation of the second information; and a control means 16 for controlling the power source supply means 17 so as to prohibit power source supply when the extended information is stored in the first storing means 14. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an electronic device.

  A GPS system that receives a signal (ephemeris information) from a GPS satellite and performs a positioning calculation uses the position information and time information of the satellite included in the ephemeris information for the positioning calculation. A technique for predicting an ephemeris using ephemeris extended information acquired in advance when ephemeris information cannot be received by this GPS system is known (see Patent Document 1).

JP 2008-3092 A

  Generally, the ephemeris extended information is used in a situation where the ephemeris information cannot be received. However, since it takes about 30 seconds to receive the ephemeris information, using the ephemeris extended information even in a state where the ephemeris information can be received can reduce the time and power consumed for receiving the ephemeris information. On the other hand, the older the ephemeris extension information used, the greater the error included in the ephemeris predicted value. Under such conditions, there has been a problem that studies on appropriately using the ephemeris extended information have not been made on electronic devices equipped with GPS devices that are battery-powered.

The electronic device according to the present invention includes a positioning unit that acquires position information using ephemeris information or ephemeris prediction information from a satellite, and a positioning unit so that position information can be acquired at predetermined intervals while the power switch is off. a power supply for supplying power supply means, so as to prohibit the first storage means for storing the ephemeris extension information required for calculating the ephemeris prediction information, the power supply if the ephemeris extension information stored in the first storage means Control means for controlling the power supply means, and when the positioning means acquires the position information before acquiring the ephemeris information from the satellite after the power switch is turned on , the positioning means is based on the information stored in the first storage means. The position information is acquired using the ephemeris prediction information calculated in the above.

  In the electronic device according to the present invention, the extended information of the GPS system can be appropriately used.

It is a block diagram explaining the structural example of the electronic camera by one embodiment of this invention. It is a flowchart explaining the flow of the process which CPU performs at the time of ON operation. It is a flowchart explaining the flow of the process which CPU performs at the time of off operation.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration example of an electronic camera 1 according to an embodiment of the present invention. In FIG. 1, an electronic camera 1 includes a photographing optical system 11, an image sensor 12, an AFE / TG (Analog front end / Timing generator) circuit 13, a built-in memory 14, a display unit 15, a CPU 16, and power control. A circuit 17, an operation member 18, an external interface 19, and a GPS module 20 are provided. A memory card 50, a wireless circuit 60, and a battery 70 are attached to the electronic camera 1.

  The photographing optical system 11 includes a plurality of lens groups including a zoom lens and a focusing lens, and forms a subject image on the light receiving surface of the image sensor 12. In order to simplify FIG. 1, the photographing optical system 11 is shown as a single lens.

  The image sensor 12 is configured by a CCD image sensor, a CMOS image sensor, or the like in which the light receiving elements are two-dimensionally arranged on the light receiving surface. The image sensor 12 photoelectrically converts a subject image by a light beam that has passed through the photographing optical system 11 to generate an analog image signal. The analog image signal is input to the AFE / TG circuit 13.

  The AFE / TG circuit 13 generates a predetermined timing signal in response to an instruction sent from the CPU 16 and supplies it to the image sensor 12. The image pickup device 12 is driven and controlled by the timing signal, whereby the image pickup timing by the image pickup device 12 and the readout timing of the analog image signal from the image pickup device 12 are controlled.

  The AFE / TG circuit 13 further performs analog processing such as correlated double sampling and gain adjustment on the analog image signal and converts the image signal after the analog processing into digital image data. The digital image data is subjected to various types of image processing (color interpolation processing, gradation conversion processing, contour enhancement processing, white balance adjustment processing, etc.) by the CPU 16.

  The built-in memory 14 is composed of a non-volatile memory, and temporarily stores digital image data before and after image processing by the CPU 16 and during processing, and stores programs executed by the CPU 16 and EE data described later. The display unit 15 is configured by a liquid crystal panel, and displays an image, an operation menu screen, and the like according to an instruction from the CPU 16.

  The CPU 16 controls the operation performed by the electronic camera 1 by executing a program stored in the built-in memory 14. The CPU 16 further monitors the operation signal input from the operation member 18 and instructs the power supply control circuit 17 about the start / end of power supply. When the battery 70 is loaded in the electronic camera 1, the operation signal monitoring function by the CPU 16 is always operated.

  Thus, when the CPU 16 receives an operation signal indicating an operation of turning on the main switch, the CPU 16 instructs the power supply control circuit 17 to start power supply and starts a predetermined power-on process. When the CPU 16 receives an operation signal indicating an operation of turning off the main switch, the CPU 16 performs a predetermined power-off process, and instructs the power supply control circuit 17 to end power supply after the power-off process is completed.

  The power supply control circuit 17 is configured to be able to control supply / non-supply of power to the GPS module 20 and power to other blocks independently. That is, it is possible to operate only the GPS module 20 with the main switch of the electronic camera 1 turned off, or to deactivate only the GPS module 20 with the main switch of the electronic camera 1 turned on. . The setting to activate / deactivate the GPS module 20 is set in advance by a menu operation, and the setting content is stored in the built-in memory 14.

  In the present embodiment, a case where the setting of “operating the GPS module” is performed will be described as an example. The CPU 16 operates the GPS module 20 with the main switch of the electronic camera 1 being turned off when the “GPS module is activated” setting and the “GPS module sleep flag is on”. When the “GPS module is activated” setting and the “GPS module sleep flag is off”, the CPU 16 deactivates the GPS module 20 while the main switch of the electronic camera 1 is turned off. The on / off setting of the GPS module sleep flag will be described later. Further, the CPU 16 when the setting of “operating the GPS module” is not performed always deactivates the GPS module 20 regardless of the state of the main switch.

  The operation member 18 includes a main switch, a release button, a menu switch, and the like. The operation member 18 sends an operation signal corresponding to each operation such as a main switch operation, a release operation, and a menu selection operation to the CPU 16.

  The GPS module 20 receives radio waves from the GPS satellites 201 and 202, and performs positioning (latitude, longitude, altitude) calculation using the ephemeris information carried on the received signal. In FIG. 1, only two of the four GPS satellites used for positioning are illustrated. The positioning information calculated by the GPS module 20 is overwritten and stored in a predetermined area of the nonvolatile memory 20b in the GPS module 20. Further, the almanac and ephemeris information received by the GPS module 20 is also overwritten and stored in a predetermined area (different from the positioning information storage area) of the nonvolatile memory 20b.

  The GPS module 20 supplied with power from the power control circuit 17 repeatedly calculates positioning information. Therefore, the latest information is stored in the nonvolatile memory 20b. When the setting is made to store the positioning information of the shooting location in association with the captured image, the CPU 16 generates an Exif format image file including the captured image data and the positioning information when the shooting is performed, and the memory card 50. Record the image file.

  The Exif format image file is obtained by embedding data such as thumbnail images and shooting information in image data in the JPEG image format. The CPU 16 reads the latest positioning information from the nonvolatile memory 20b at the time of shooting, and generates an image file including the read positioning information.

<Positioning process>
Here, the positioning process by the GPS module 20 will be described. The GPS module 20 acquires almanac information and ephemeris information from signals transmitted from the GPS satellites 201 and 202, respectively. The almanac information includes information related to the orbits of all GPS satellites, and the ephemeris information includes position information and time information for each satellite. The GPS module 20 selects four satellites used for positioning based on the almanac information, and calculates its own position based on signals transmitted from the selected four satellites.

  When positioning is repeatedly performed, if the orbit information, position, and time information of the satellite are stored in the nonvolatile memory 20b, the stored information can be used at the next positioning. However, the position information of the satellite requires new position information when a predetermined time (for example, 4 hours) elapses, and the orbit information requires new orbit information when a predetermined period (for example, 4 weeks) elapses. . Therefore, when the measurement interval is increased from the previous measurement, it is not appropriate to use the stored information. Therefore, it is necessary to newly acquire at least one of the satellite ephemeris information and the almanac information. The reason why new information is required after a predetermined time has elapsed is that the transmission information from the satellite is prediction information indicating the position and orbit of the satellite, so the error between the actual satellite position and satellite orbit over time Because it increases.

  In general, the state where it is necessary to newly acquire the almanac information and the ephemeris information at the time of positioning is “cold”, the state where only the ephemeris information needs to be newly acquired at the time of positioning is “warm”, and the almanac information and the ephemeris at the time of positioning. A state in which information does not need to be newly acquired is called “hot”. The GPS module 20 changes information to be newly acquired depending on which of these three states is applicable. If it is not necessary to acquire new information, the time required to acquire the information can be shortened, so the positioning time is (when “cold” starts)> (when “warm” starts)> (when “hot” starts) Have the relationship.

<Ephemeris prediction process>
Regarding the ephemeris information of the satellite, the time until new information is required is referred to as an ephemeris effective time. In the technique described in Patent Document 1, an ephemeris having a longer time (for example, 4 weeks) than an ephemeris effective time (for example, 4 hours) is calculated by prediction calculation using ephemeris extended information (hereinafter referred to as EE data).

  The CPU 16 of the present embodiment has a function of omitting acquisition of ephemeris information by using an ephemeris prediction value instead of newly acquiring ephemeris information in a state “warm” in which ephemeris information needs to be newly acquired at the time of positioning. Prepare. If the acquisition of the ephemeris information is omitted, the positioning can be performed in the same short time as the “hot” start while the “warm” start.

  In the present embodiment, the process using the ephemeris predicted value is applied in a state where the main switch of the electronic camera 1 is turned off. That is, the ephemeris information is periodically acquired by the GPS module 20 even when the main switch of the electronic camera 1 is turned off so that the GPS module 20 can always perform “hot” start. At this time, when the predicted ephemeris value is obtained, the activation of the GPS module 20 in the main switch off state is omitted. The calculation method of the ephemeris predicted value is the same as that in Patent Document 1.

<Acquisition of EE data>
The case where the predicted ephemeris value is obtained refers to a state in which the electronic camera 1 has valid EE data. The information transmitted to the ground by the GPS satellites 201 and 202 is originally transmitted from the ground to each satellite by the United States operating the GPS system. The United States provides information (EE data) necessary for predicting the position of each GPS satellite separately from the information transmitted by each GPS satellite to the ground. By performing a predetermined prediction calculation using this EE data, the same information (ephemeris predicted value) as the ephemeris transmitted by each GPS satellite can be obtained.

  In this embodiment, EE data is acquired via a network from a server 301 (FIG. 1) in which EE data is stored, and the EE data is stored in a predetermined area of the built-in memory 14 in the electronic camera 1 in advance. deep. Acquisition of EE data via the network is performed, for example, by wirelessly connecting the access point 302 connected to the network and the wireless circuit 60 attached to the electronic camera 1. The EE data received by the radio circuit 60 is acquired by the CPU 16 via the external interface 19.

  Instead of using the radio circuit 60, a personal computer (PC) 303 may be used. In this case, the PC 303 is connected to the network, and the PC 303 and the external interface 19 are connected via a USB cable. As a result, the CPU 16 acquires EE data via the external interface 19.

  In addition, the memory card 50 is attached to the memory card holder of the PC 303, the EE data acquired by the PC 303 via the network is recorded in the memory card 50, and the CPU 16 is attached to the electronic camera 1 by attaching the memory card 50 to the electronic camera 1. It can also be configured to read EE data from the memory card 50.

  The EE data also has a valid period. This is because the EE data also corresponds to the prediction information indicating the satellite position and the satellite orbit, and the error between the actual satellite position and the satellite orbit increases with time. The valid period of EE data is, for example, 4 weeks. Since the error gradually increases with the passage of time, the degree of error differs between the initial stage and the end of the four weeks.

  In the present embodiment, the GPS module sleep flag described above is used to determine whether or not to acquire ephemeris information in a state where the main switch of the electronic camera 1 is turned off. The following description will focus on the process of setting the GPS module sleep flag and the power-off process of the electronic camera 1 in accordance with the state of the GPS module sleep flag.

<Setting the GPS module sleep flag>
The GPS module sleep flag is set when the electronic camera 1 is powered on. FIG. 2 is a flowchart for explaining the flow of processing performed by the CPU 16 when the main switch is turned on. When the battery 70 is loaded in the electronic camera 1 and the main switch is turned on (power-on operation) from the off state, the CPU 16 sends an instruction to the power supply control circuit 17 to block each block in the electronic camera 1. In addition, the power supply to the GPS module 20 is started and the processing shown in FIG. 2 is started.

  In step S1 of FIG. 2, the CPU 16 determines whether or not EE data has been downloaded. When the EE data is stored in the predetermined area of the built-in memory 14, the CPU 16 makes a positive determination in step S1 and proceeds to step S2. If the EE data is not stored in the predetermined area of the built-in memory 14, the CPU 16 makes a negative determination in step S1, and proceeds to step S7. Downloading of EE data is performed in advance using the maintenance of the electronic camera 1 or the like. For example, the electronic camera 1 is connected to the network as described above, and a predetermined download process is activated by a menu operation to acquire EE data.

  In step S2, the CPU 16 confirms the valid period of the EE data and proceeds to step S3. In this embodiment, the valid period is 4 weeks from the time of acquisition of EE data (when stored in the built-in memory 14). In step S3, the CPU 16 determines whether it is within the valid period. If the CPU 16 is within the valid period of the stored EE data, the CPU 16 makes an affirmative decision in step S3 and proceeds to step S4. If not, the CPU 16 makes a negative decision in step S3 and proceeds to step S7.

  In step S4, the CPU 16 determines whether or not the EE data needs to be updated. The CPU 16 makes a negative determination in step S <b> 4 and proceeds to step S <b> 5 when the number of days elapsed since the acquisition of the stored EE data is within two weeks, for example. The CPU 16 makes a negative determination in step S4 when the number of days elapsed since the acquisition of the stored EE data exceeds two weeks, and proceeds to step S6.

  In step S5, the CPU 16 turns off the GPS module sleep flag and ends the process of FIG. In step S6, the CPU 16 displays an EE data download recommendation message on the display unit 15 and proceeds to step S5. As described above, the error of the EE data is different in the initial period and the end of the effective period, so when the end of the effective period in which the error becomes large is reached, for example, “please update the EE data”. A message is displayed to prompt the user to acquire EE data.

  In step S <b> 7, the CPU 16 turns on the GPS module sleep flag and ends the processing in FIG. 2. The CPU 16 after the processing according to FIG. 2 performs predetermined processing in response to an operation signal from the operation member 18 such as shooting processing corresponding to the release operation and menu processing corresponding to the menu operation.

<Power off process>
FIG. 3 is a flowchart for explaining the flow of processing performed by the CPU 16 when the main switch is turned off. When the CPU 16 receives an operation signal indicating a main switch-off operation (power-off operation), the CPU 16 activates the process of FIG.

  In step S21 of FIG. 3, the CPU 16 determines whether or not the GPS module sleep flag is on. When the GPS module sleep flag is turned on, the CPU 16 makes a positive determination in step S21 and proceeds to step S22. If the GPS module sleep flag is off, the CPU 16 makes a negative determination in step S21 and proceeds to step S23.

  In step S22, the CPU 16 sends an instruction to the power supply control circuit 17, continues the power supply to the GPS module 20, and proceeds to step S24. This is because the GPS module 20 performs the positioning process even in the power-off state of the electronic camera 1. Thus, the ephemeris information is acquired at a predetermined timing so that the “hot” start can always be performed.

  In step S24, the CPU 16 sends an instruction to the power supply control circuit 17, instructs the end of power supply to blocks other than the GPS module 20, and finishes the process shown in FIG.

  On the other hand, in step S23 that proceeds with a negative determination in step S21, the CPU 16 sends an instruction to the power supply control circuit 17, stops the power supply to the GPS module 20, and proceeds to step S24. This is because the positioning process is not performed by the GPS module 20 in the power-off state of the electronic camera 1. This is because the “hot” start can be performed using the ephemeris predicted value without acquiring the ephemeris information.

According to the embodiment described above, the following operational effects can be obtained.
(1) The electronic camera 1 acquires position information at predetermined intervals while the power switch 18 is off and the GPS module 20 that acquires position information using ephemeris information from the satellites 201 and 202 or the ephemeris predicted value. A power control circuit 17 that supplies power to the GPS module 20, a built-in memory 14 that stores EE data necessary for calculating the ephemeris prediction value, and a power supply when the EE data is stored in the built-in memory 14. And a CPU 16 for controlling the power supply control circuit 17 so as to inhibit the power supply. Thereby, EE data can be used appropriately. That is, since the GPS module 20 does not acquire the ephemeris information when the power switch 18 is turned off when the stored EE data exists, battery consumption can be suppressed. It is particularly suitable for equipment driven by the battery 70.

(2) When the GPS module 20 performs a positioning calculation before acquiring ephemeris information from the satellites 201 and 202 after the power switch 18 is turned on, the ephemeris calculated based on the storage information (EE data) stored in the built-in memory 14. The positioning calculation is performed using the predicted value. Thereby, EE data can be used appropriately. That is, by performing positioning calculation using the predicted ephemeris value without waiting for the acquisition of ephemeris information, positioning can be performed in the same short time as the “hot” start while being the “warm” start.

(3) When the EE data is not stored in the built-in memory 14 and when a predetermined period has elapsed since the EE data is stored in the built-in memory 14, the CPU 16 The power supply to the GPS module 20 is permitted. If the EE data does not exist or exists, but the valid period has passed, it is inappropriate to use the ephemeris predicted value. Since the GPS module 20 acquires the ephemeris information even when the power switch 18 is off, the latest ephemeris information can always be obtained.

(4) The memory module 20b further stores the ephemeris information acquired by the GPS module 20 from the satellites 201 and 202 while the power switch 18 is in the off state. The GPS module 20 includes the satellites 201 and 202 after the power switch 18 is turned on. When the positioning calculation is performed before the ephemeris information is acquired, the positioning calculation is performed using the information stored in the memory 20b. By performing the positioning calculation using the stored information without waiting for the acquisition of the ephemeris information, it is always possible to perform the positioning in a short time after starting “hot”.

(Modification 1)
In step S4 described above, the necessity of updating the EE data is determined based on the number of days elapsed since the acquisition of the EE data (step S4), but the actually acquired ephemeris information is compared with the predicted ephemeris value to determine the EE data. It may be necessary to determine the need for updating. In this case, the CPU 16 calculates an ephemeris predicted value using the EE data stored in the built-in memory 14, and compares this predicted value with the ephemeris information actually acquired by the GPS module 20. If the difference between the two is equal to or less than the predetermined value, the CPU 16 makes a negative determination in step S4 and proceeds to step S5. If the difference between the two exceeds a predetermined value, the CPU 16 makes a positive determination in step S4 and proceeds to step S6.

(Modification 2)
In the above description, an example has been described in which it is determined whether or not to acquire ephemeris information in a state where the main switch of the electronic camera 1 is turned off. In a state where the main switch of the electronic camera 1 is turned on, whether or not to acquire the ephemeris information may be determined as follows.

  The CPU 16 sends an instruction to the GPS module 20 and performs positioning calculation using the almanac and ephemeris information stored in a predetermined area of the non-volatile memory 20b in “hot” in which it is not necessary to newly acquire ephemeris information at the time of positioning. To do.

  In the “warm” in which only the ephemeris information needs to be newly acquired at the time of positioning, the CPU 16 uses the ephemeris prediction value instead of newly acquiring the ephemeris information so as to omit the acquisition of the ephemeris information to the GPS module 20. Send instructions. As a result, positioning can be performed in the same short time as the “hot” start while the “warm” start is performed. Further, the CPU 16 performs positioning calculation using the ephemeris predicted value, and instructs acquisition of new ephemeris information. When new ephemeris information is acquired, the positioning calculation using the latest ephemeris information is performed as necessary, and the positioning calculation result using the latest ephemeris information is adopted instead of the positioning calculation result using the ephemeris predicted value. .

  The acquired new ephemeris information is updated and recorded in a predetermined area of the nonvolatile memory 20b. By controlling in this way, the positioning calculation result can be obtained quickly and the latest ephemeris information can be obtained.

  In the “cold” in which the ephemeris information and the almanac information need to be newly acquired at the time of positioning, the CPU 16 sends an instruction to the GPS module 20 to obtain the almanac information and the ephemeris information and perform the positioning calculation.

(Modification 3)
A message may be displayed on the display unit 15 when EE data is not stored in a predetermined area of the built-in memory 14 and when the validity period of the stored EE data has expired. In this case, the CPU 16 displays a message “positioning takes time” on the display unit 15 before proceeding to step S7, for example. By notifying in advance that a “warm” start is necessary, it is possible to prevent a misunderstanding that a “warm” start has occurred when a “hot” start is expected.

(Modification 4)
Although the electronic camera 1 equipped with the GPS module 20 has been described as an example, the present invention may be applied to electronic devices such as a mobile phone, a video camera, and a personal computer equipped with the GPS module 20.

  The above description is merely an example, and is not limited to the configuration of the above embodiment.

DESCRIPTION OF SYMBOLS 1 ... Electronic camera 14 ... Built-in memory 15 ... Display part 16 ... CPU
17 ... Power control circuit 18 ... Operation member 19 ... External interface 20 ... GPS module 50 ... Memory card 60 ... Wireless circuit 70 ... Battery 201, 202 ... GPS satellite 300 ... Network 301 ... Server

Claims (5)

Positioning means for acquiring position information using ephemeris information or ephemeris prediction information from a satellite;
Power supply means for supplying power to the positioning means so that position information can be acquired at predetermined intervals while the power switch is in an off state;
First storage means for storing ephemeris extended information necessary for calculating the ephemeris prediction information ;
Control means for controlling the power supply means so as to prohibit the power supply when the ephemeris extended information is stored in the first storage means ,
When the positioning means acquires position information before acquiring the ephemeris information from the satellite after the power switch is turned on, the positioning means uses ephemeris prediction information calculated based on the storage information by the first storage means. An electronic device characterized in that the position information is acquired . Positioning means for acquiring position information using ephemeris information or ephemeris prediction information from a satellite;
Power supply means for supplying power to the positioning means so that position information can be acquired at predetermined intervals while the power switch is in an off state;
First storage means for storing ephemeris extended information necessary for calculating the ephemeris prediction information ;
Control means for controlling the power supply means so as to prohibit the power supply when the ephemeris extended information is stored in the first storage means,
When the ephemeris extended information is not stored in the first storage means, and when a predetermined period has elapsed since the ephemeris extended information is stored in the first storage means, the control means respectively An electronic apparatus characterized by permitting power supply to the positioning means while a power switch is in an OFF state. The electronic device according to claim 2 ,
A second storage means for storing ephemeris information acquired from the satellite by the positioning means while the power switch is off;
The positioning means obtains position information using the ephemeris information from the second storage means when obtaining position information before obtaining the ephemeris information from the satellite after the power switch is turned on. Features electronic equipment. The electronic device according to claim 2 or 3 ,
If the ephemeris extension information is not stored in the first storage means, and when the ephemeris extension information in the first storage means is elapsed predetermined period is stored, notifying each performing a predetermined notification An electronic device comprising means. In the electronic device as described in any one of Claims 1-4 ,
The electronic device is characterized in that the power supply means supplies power to the positioning means using power supplied from a battery.

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